


Sweet But Psycho

by Sunset_Curve



Series: The Kayce Mikaelson Chronicles [4]
Category: Legacies (TV 2018), The Umbrella Academy (TV), The Vampire Diaries & Related Fandoms, The Vampire Diaries (TV), The Vampire Diaries - L. J. Smith
Genre: Apocalypse, End of the World, F/M, Hybrids, I'm Bad At Tagging, Vampires, Werewolves, Witches, tribrid
Language: English
Status: In-Progress
Published: 2021-01-13
Updated: 2021-01-12
Packaged: 2021-03-17 10:20:29
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 3,530
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28723494
Author URL: https://archiveofourown.org/users/Sunset_Curve/pseuds/Sunset_Curve
Summary: Inbar Lavi as Kayce MikaelsonDavid Castsñeda As Diego HargreevesTUA Cast as ThemselvesThe Originals/Legacies Cast as ThemselvesThe Umbrella AcademySeason 1Diego Hargreeves x OC
Relationships: Diego Hargreeves/Original Female Character(s)
Series: The Kayce Mikaelson Chronicles [4]
Series URL: https://archiveofourown.org/series/1308317
Kudos: 6





	1. Chapter One

**Episode 1: We Only See Each Other At Weddings and Funerals Part 1**

****

....

Kayce smiled at her niece as her phone rings she's helping Hope with her magic training "that was good Hope... Keep practicing I'll be back in a minute I've gotta take this."

The tribrid smiled at her aunt "okay" then she went back to practicing the spell the two were working on.

Kayce answers the phone a smile slipping onto her face once again "hey you."

"Hey, Kace."

She can instantly hear in his voice that something is wrong "what's going on Diego?"

There's a pause on the other end "my dad died last night"

"I know he wasn't a good father but I'm sorry for your loss D... Do you want me to come up there for the funeral with you?"

"Yes, if you can... I know you're busy with Hope and everything but facing this with you would be a lot easier than facing it alone and by it I mean my siblings that I haven't seen in years"

"Hey, I'll be there soon okay? Hope will be alright here at the school without me for a little while"

There's a relieved tone in his voice after she said that "Thank you Kayce"

She can't help but smile "you're welcome D... You know all you gotta do is ask and I'm there... I'll see you soon"

"Alright I'll text you the address and I'll see you there"

Kayce hangs up and goes back over to her niece "hey kiddo."

Hope smiles at her aunt "you gotta go?"

Kayce smiles "yeah but I'll be back before you know it."

Hope grins teasingly at her aunt "and when am I gonna get to meet them? The man or woman that has managed to do something that no other man or woman has and that is to catch your attention, I've heard the stories from uncle Kol"

Kayce gives her niece a look "How do you even know there is someone?"

The teenager smirks at her aunt... Reminding Kayce so much of her brother "Because ever since you dropped in six months ago, I've noticed the secretive phone calls the texts that make you smile that goofy smile, that says I'm in love."

Kayce chuckled at the girl "You are too smart for your own good kiddo... Just like your dad, you know that? But fine there is a guy, his name is Diego and we met 3 years ago and that's all I'm telling you for now but he does need me right now but hey you need me for anything you call and I'll be there because you are my family and I put that above everything"

Hope smiles at her "I know aunt Kayce but go I'll call if I need you"

Kayce hugs her niece and kisses her on the head "I love you kiddo"

Hope smiled at her "love you too Aunt Kayce"

Kayce goes to the room she was given at the school and packs a bag grabbing and heading to where her car is parked she gets stopped by Alaric "Kayce you leaving?"

She smiles at him "yeah I'm heading out for a while but I'll be back soon to check on Hope."

He nods at her "see you later then"

She walks out to her car gets in and starts her journey up to New York to meet up with Diego.

She knows all about his past and everything, he told her everything about the way his father treated them and that he didn't even give them names just numbers and left Grace their mother to name them, he told her about his brother Five's disappearance and his other brother Ben dying and absolutely everything else there is to know about him and in return, she told him everything as well the way her sister was taken by her aunt, the death of her baby brother and how it drove her parents to turn her and her siblings into monsters, how Mikael her father hunted them down for centuries and everything there was to know about her and her family she even told him all about her niece Hope and her promise to her brother to look after her.

To say that Kayce and Diego bonded over their shitty fathers and daddy issues would be a major understatement.

Kayce understood Diego in a way that nobody else had ever been able to do and vice versa Diego understood Kayce in a way that nobody outside of her family had ever been able to do maybe it was due to their somewhat similar upbringings but whatever the reason it brought them together and they taught each other how to love, neither of them had been in love before they met.

It took Kayce maybe four hours to get to the address that was texted to her, she stared at the house across from where she parked her car in appreciation but it was nowhere near as big as some of the houses she had lived in with her brother.

She checks her hair and everything before stepping out of the car and walking up the house, opening the gate and walking into the house as the door was unlocked only to be met with a knife coming right at her head, she rolled her eyes catching the knife before it hit her.

She laughs calling out "you know one of these days that's actually gonna hit me... maybe if you're lucky"

Kayce hears him chuckle "sorry about that.... actually no I'm not"

She smiles as he pulls her into a hug "clearly as you do it almost every time I walk through the door unannounced"

he picks her up into another hug. "I have missed you though Kace"

She smiled with a chuckle "I missed you too"

He lets her down "How's Hope doing?"

Kayce smiles talking about her niece "as good as can be expected after everything she's been through"

"At least she still has an amazing aunt that is willing to protect her no matter what"

Kayce smiles pecking him on the lips "yeah I gave my brother my word I'd look after her and I intend to do exactly as I said I would"

Diego grabs her hand and pulls her towards the living room where the others are gathered.


	2. Chapter Two

**Episode 1: We** **Only See Each Other At Weddings and Funerals Part 2**

****

*******

Diego starts pulling her towards the living room but changes direction towards where his mom is "I was gonna take you to meet the others but first I want you to meet my mom." 

Kayce gives him a playful look "Oohh finally after all I've heard about her" they walk into the kitchen where they find Grace.

Diego smiles "Mom?"

Grace turned around with a smile "Diego"

The boy smiled back at her "Mom, I want you to meet someone, this is Kayce and Kayce this is my mom Grace"

Kayce smiled Diego has told her so much about Grace and she finally got the chance to meet her "it's nice to _finally_ meet you"

Grace smiles at the brunette girl in front of her "Hello Kayce, it's nice to meet you."

Kayce smiled at her again Diego grabs her hand again and goes to pull her out of the room "we gotta go meet the others" then she lets him pull her out of the room.

Kayce smirks playfully at him "you are such a momma's boy!" He gives her an unamused look but Kayce just chuckles and grabs his chin "but it's okay cause it's cute"

Diego rolled his eyes and lead her into the living room where they are meeting to plan the memorial for their father. The two are as usual the last ones in there turning the attention to them Kayce smirks as she takes the seat beside Diego. Luther looks at her "who are you? and why are you here?"

Kayce just smirks at him "well I'm Kayce, Kayce Mikaelson, and frankly why I'm here doesn't really concern you but if you must know I'm here because Diego asked me to come and if you don't like it well that's just too damn bad because I'm not leaving." 

Klaus grins from behind the bar where he is fixing himself a drink "I like her, Diego."

Luther stands up "I guess we should get this started, so I figured we could have a sort of memorial service in the courtyard at sundown. Say a few words, just at dads favorite spot" 

Allison looks at Luther "Dad had a favorite spot?"

Luther nods "yeah you know under the oak tree" everyone looks confused not knowing that he had a favorite spot "we used to sit out there all the time. None of you ever did that?"

Kayce leans over as if to whisper to Diego but says it loud enough that everyone can hear "well I guess we know who the favorite was now" she gets a glare from Luther and a chuckle from Diego and Klaus as he makes his way over "Will there be refreshments? Tea? Scones? Cucumber sandwiches are always a winner." 

Kayce smirks "Tequila is always a nice touch too" 

Which earns her a smile from Klaus "I like the way you think" and a chuckle from Diego who was used to stuff like that from his girlfriend, while Vanya and Allison ignore her, and Luther once again glares at the Original. 

Luther turns his attention back to his brother "What? No, and put that out. Dad didn't allow smoking in here"

Allison looks at her brother "is that my skirt?"

Klaus sits his drink down "What?... Oh, yeah this... I found it in your room, it's a little dated, I know but it's very breathy on the bits" Kayce smirks at him liking his attitude. 

"Listen up. Still, some important things that we need to discuss alright?" Luther said turning the attention back to him.

Diego looks towards Luther "Like what?"

"Like the way, he died"

Diego roll his eyes and mutters "here we go" 

Vanya speaks for the first time since the meeting started "I don't understand I thought they said it was a heart attack"

Luther nods "yeah according to the coroner"

Vanya looks at Luther "well wouldn't they know?"

"Theoretically"

Allison looks confused "Theoretically?" 

"I'm just saying, at the very least something happened. The last time that I talked to Dad, he sounded strange" 

"Oh, Quelle surprise!" Klaus gurgles out with whatever he is drinking in his mouth.

"Strange how?" Allison questions.

"He sounded on edge. Told me I should be careful who to trust" 

Diego stands up walking towards Luther "Luther, he was a paranoid, bitter old man who was starting to lose what was left of his marbles"

Luther shakes his head disagreeing "no. he must have known something was going to happen." Kayce stays put in her seat as this really doesn't involve her.

Luther looks at Klaus "I know you don't like to do it but I need you to talk to Dad"

Allison scoffs as Klaus looks at Luther "I can't just call Dad in the afterlife and be like, "Dad, could you just stop playing tennis with Hiter for a moment and take a quick call?" 

Kayce snorts with an eye roll "bet Mikael is right there with them" she gets a weird look from everyone but Diego since he knows what she's talking about.

"What?" The question came from Luther but Kayce just brushes off their stares and stands up beside Diego. "You had your crappy father and I had mine I'm just saying that mine is right there with yours playing tennis with Hitler... would not surprise me in the slightest.

Luther decided to direct the conversation back to Klaus "Since when? That's your thing"

Klaus looked at him "I'm not in the right... frame of mind" Kayce smirks at the boy... she can smell the drugs on him as Allison looks at Klaus "You're high?"

He nods "yeah, yeah. I mean how are you not, listening to this nonsense?" 

Luther gave Klaus a look "Well sober up this is important"

Klaus sighs as Luther continues "then there's the issue of the missing monocle"

Kayce rolls her eyes as Diego looks at Luther "Who gives a shit about a stupid monocle?" 

"Exactly" Luther agrees looking at Diego, but he can't just leave it at that he has to keep talking "so whoever took it, I think it was personal. Someone close to him, someone with a grudge"

Kayce glares at Luther already getting exactly what he's saying and by the look on Diego's face, she can tell he figured it out as well. 

Klaus looks at his brother "where are you going with this?"

Diego comes in "Oh isn't it obvious Klaus? He thinks one of us killed Dad"

Luther stays silent as the others look at him and Klaus is the first to speak "You do?"

Vanya is the next to speak "how could you think that?" 

Diego looks at Luther "Great job, Luther. Way to lead"

Diego walks out of the room as Klaus gets up from the sofa "You're crazy, man, You're crazy. Crazy"

He starts walking out of the room. "I've not finished"

"Okay sorry, I'm just gonna go murder mom be right back" Klaus sasses. 

Allison and Vanya leave the room as well leaving Luther alone with Kayce.... probably not the best idea, she glares at the large man already knowing a lot about him from Diego to know that she doesn't like him "listen up, space boy... I'm gonna be honest here, I don't like you and I will give you one warning, and here it is, you piss me off and I don't care who you think you are, or that you are 3 times my size... I will lay you out so fast you won't even know what hit you. Word of advice pissing a Mikaelson off is never a good idea, we are known to have rather nasty tempers... now have a nice day... I am going to go and find Diego" 

With that, she leaves Luther in the living room and sets off to find her boyfriend. ****

**Notes for the Chapter:**

> I love them so much already, I know Kayce hasn't had much screentime if you will in this chapter but that's because it was more centered around Diego and his siblings, I meant what I said about Kayce and Luther they are going to clash so much and it's gonna be so much fun to write


	3. Chapter Three

**Episode 1: We Only See Each Other at Weddings and Funerals Part 3**

****

*******

Kayce focused her senses to find Diego and they lead her upstairs she finds him sitting on a bed in what she assumes was his bedroom as a child, she smiled at him, "Hey you"

He looks up and smiled back at her "hey Kace" 

She sat beside him on the bed "so I just had a little conversation with your brother." 

Diego snorts giving her a knowing look "let me guess you threatened him?"

Kayce shoves him playfully "no, I just gave him a warning not to piss me off."

Diego gives her a look "Well Luther tends to piss almost everyone off, so that warning might have been in vain."

She shrugs grinning at him "at least I _gave_ him a warning" 

He looks at her for a moment "true" he stands up, offering her a hand to pull her to her feet. "come on, I'll give you the official tour of the house, and maybe if we see them I'll introduce you to the rest of them, officially." Kayce took the hand and let him pull her up and they walked out of the room and back downstairs they get through a few rooms and as they get to the living room music starts playing. 

_♪ Children behave ♪_

Kayce smiles "oh my god I love this song" Diego gives her a little smirk and shuts the door, Kayce gives him a smirk of her own as Diego turned back to her "dance with me?" he grabs her hand and twirls her around before doing his own little dance.

_♪ That's what they say_   
_When we're together ♪_

__

_♪ And watch how you play ♪_

__

_♪ They don't understand_   
_And so we're ♪_

__

_♪ Running just as fast as we can ♪_   
_♪ Holdin' on to one another's hand ♪_   
_♪ Tryin' to get away into the night ♪_   
_♪ And then you put your arms around me ♪_

Kayce laughed as she gets spun around again. 

Then their little dance is interrupted by a loud crash of thunder coming from the back of the house and the music stops as everybody stops dancing around and runs out to see what's going on.

Luther and Allison are the first ones out followed by Kayce and Diego, then Vanya and they are all staring at the portal thing in the sky. 

Vanya is the first to speak "What is it?" 

"Don't get too close!" Allison warns. 

Diego rolls his eyes "Yeah No Shit!"

Kayce smacks his arm "there is a big blue portal in the sky, the likes of that I have never seen before so stop being sassy" Diego gives her a look as she steps forward taking a breath and focusing, and after a moment Kayce steps back beside Diego "Well it's definitely not magic" 

Diego looks at her "you've never seen anything like it? Ever?"

Kayce shakes her head giving her boyfriend a look "nope I've seen some pretty weird shit but this is a new one even for me"

Luther ignores the couple and starts talking "Looks like some sort of temporal anomaly. Either that or a miniature black hole. One of the two." 

Kayce rolls her eyes with a snort at Diego's response to his brother "Pretty big difference there, Paul Bunyan." 

Klaus comes running out of the house carrying a fire extinguisher "Out of the way!"

Luther looks at his brother "What are you--" Klaus sprays the portal and upon seeing that it did nothing he throws the fire extinguisher into the portal. 

Allison looks at him "What is that gonna do?"

He shrugs at her yelling "do you have a better idea?" there is a crackling of electricity and Luther steps in front of the group "Whoa, whoa, whoa. Everybody get behind me" and of course Diego has to step forward as well "yeah get behind us" 

Klaus looks at the portal then at his family "I vote for running, C'mon!" he grabs ahold of Kayce's arm but she shakes him off and grabs his wrist so he won't run. 

There is more crackling electricity and screaming then a kid falls through the portal and the thunder fades and the portal disappears and everybody is staring at the kid in shock well except for Kayce because she doesn't know who he is. Klaus is the first to speak "Does anyone else see little number Five? or is it just me?" 

Five looks down noticing that he is wearing a suit far too big for his now 13-year-old body "Shit" 

Now everybody is gathered in the kitchen as Five stats making himself his favorite sandwich peanut butter and marshmallow, he looks at his siblings with a sigh "What's the date? The exact date."

Vanya looks at him "the 24th"

He looks at her "of what?"

"March"

Five nods "good" 

Kayce looks at the boy "what the bloody hell just happened?"

Luther nods "yeah so, are we gonna talk about what just happened?" Five makes no move to answer his brother "It's been 17 years" Luther snaps at him wanting to know what the hell they just witnessed.

"It's been a lot longer than that" Five snaps back at Luther before using his powers to teleport behind Luther to get the peanut butter and marshmallows to finish making his sandwich. Luther rolls his eyes "I haven't missed that" 

Vanya looks at him "where'd you go?"

Five looks at her "the future... It's shit by the way"

"Called it" Klaus calls out happily. 

"I should've listened to the old man. You know, jumping through space is one thing jumping through time is a toss of the dice." Five notices Klaus' outfit "Nice dress"

Klaus looks down at it and smiles "Oh, well, danke!" 

Kayce nods, this surprisingly not being the weirdest thing she's ever seen "okay future boy... mind elaborating on how the bloody hell you got back here from the shitty future?"

Five looks at her for the first time "and you are?"

Kayce smirks at the grown man in the body of a 13-year-old, "Kayce Mikaelson... extraordinaire to all things weird and sadistic"

Diego shoves her shoulder giving his girlfriend a look "Kayce! You don't go telling people that, especially when they don't know you." 

She shrugs completely unbothered by the information she just gave out as an introduction "what? I'm being honest here." 

Diego shakes his head still looking at her "You know what I'm not even gonna try here" Kayce just smirks at him. 

Five looks at her for a moment "well okay then......In the end, I had to project my consciousness forward into a suspended quantum state version of myself that exists across every possible instance of time." 

Diego looks at his brother confused and not understanding a word that he said, "that makes no sense" 

Five rolls his eyes and snaps "Well, it would if you were smarter." ****

**Notes for the Chapter:**

> Kayce introducing herself to Five oh my god I can literally picture her introducing herself like that and it is completely beautiful. I literally love these two together so much they are now up in my favorite pairings with Kayce. Anyway, I hope you guys enjoy this chapter.

**Author's Note:**

> Oh my god, I am so excited about this. Yes, I decided to make their relationship pre-existing to season one of TUA and my babies are so soft for each other and I love it so much. Hope you guys enjoy this and I hope you guys are having a nice day/night whatever it is when you read this 😊😊.


End file.
